The history of the development of the prior art as it relates to a high torque fastener driving system is treated in detail in my U.S. Pat. No. 4,033,003 granted July 5, 1977. Whereas U.S. Pat. No. 3,388,411, which issued to Rudolph M. Vaughn, teaches the forming of an arcuate and undercut fastener slot having diverging sidewalls using a method requiring three separate heading blows, the Marroquin method taught by U.S. Pat. No. 4,033,003 requires two separate heading blows. This Marroquin Method One uses a hammer that develops a slot where the lateral bulges of the diverging sidewalls of the slot are continuous and uninterrupted along the entire undercut length of the slot. Although the slot so formed is generally acceptable, the hammer used in the first step of the Marroquin Method One does not develop an undercut fastener driving slot that conforms geometrically and visually to the RECESS-HI-TORQUE of MILITARY STANDARD MS 33750. Similarly, the hammer used in the Bergere method taught by U.S. Pat. No. 3,354,481 granted Nov. 28, 1967 does not develop a bowtie or "butterfly" slot that conforms exactly with the requirements of MS 33750.